上皮性嚢腫（Epithelial Cyst）の2例

Epithelial Cysts of the Central Nervous System: Report of two cases

I．はじめに

　CT, MRI等の画像診断法の進歩に伴い頭蓋内嚢腫性病変の診断は容易になりつつあり，嚢胞性腫瘍と非腫瘍性嚢胞の画像上の鑑別も可能な場合が多い．しかしながら，非腫瘍性嚢胞において，くも膜嚢腫と上皮性嚢腫（epithelial cyst）の鑑別は神経放射線学的手法によっても困難で，嚢腫壁を構成する細胞の組織学的検索によらねばならない^15）．今回，私達は臨床上，又画像診断上くも膜嚢腫が疑われたが光顕・電顕による組織学的観察により上皮性嚢腫と診断された2症例を経験したので報告する．

Two cases of epithelial cyst are reported.

Case 1. A 68-year-old female visited our hospital with a complaint of decreased visual acuity, 0.04 in the left eye, in September 1986. Visual field examination showed bitemporal hemianopsia. CT scan demonstrated nonenhancing cystic lesion involving the suprasellar re-gion. By a right frontotemporal craniotomy, the sup-rasellar cyst was explored. The wall of the cyst was partially removed to relieve pressure against both optic nerves and chiasma. Histologically, the cyst wall was lined with a single layer of non-ciliated cuboidal epithe-lium.